ios - NSMutableArray 没有像预期的那样改变事件

Question

我可以很好地循环遍历它们，但我想做的是更改背景颜色(对于 objective-c 来说仍然是新的)。这是我拥有的:

@interface MYViewController ()
@property (nonatomic, retain) NSMutableArray *listImages;
@end

@implementation MYViewController

- (void)viewDidLoad
{

    self.listImages = [[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@"bg-menuitem-highlighted.png"],
                      [UIImage imageNamed:@"bg-menuitem-highlighted.png"],
                      [UIImage imageNamed:@"bg-menuitem-highlighted.png"], nil];

    [self.listImages enumerateObjectsUsingBlock:^(id object, NSUInteger idx, BOOL *stop) {
        // do something with object
        UIImage *image = [self.listImages objectAtIndex:idx];
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleAspectFit;
        imageView.clipsToBounds = YES;
        [self.view addSubview:imageView];
        imageView.frame = CGRectMake(100*idx, 10*idx, imageView.frame.size.width + 15, imageView.frame.size.height + 15);

        [imageView.layer setBorderColor: [[UIColor blackColor] CGColor]];
        [imageView.layer setBorderWidth: 2.0];
        imageView.contentMode = UIViewContentModeCenter;

    }];
    [self.view addSubview:btnEventClick];
    [super viewDidLoad];
}

- (void)myEventDo:(DoEvent *)btnEventClick {
    NSLog(@"My event is doing!");
    int i = 0;
    for (NSString *item in self.listImages) {
        NSLog(@"hi");
        UIImage *newImage = [self.listImages objectAtIndex:i++];
        UIImageView *newImageView = [[UIImageView alloc] initWithImage:newImage];
        newImageView.backgroundColor = [UIColor redColor];
    }
}

我做错了什么？

Answer 1

您在全新的 UIImageView 上设置了 backgroundColor，然后不显示它。就个人而言，当您创建和修改这些对象时，我会创建另一个 UIImageView 对象数组。像这样的东西:

@interface otViewController ()
@property (nonatomic, retain) NSMutableArray *listImages;
@property (nonatomic, retain) NSMutableArray *listImageViews;
@end

@implementation otViewController


- (void)viewDidLoad
{

    self.listImages = [[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@"S.png"],
                       [UIImage imageNamed:@"X.png"],
                       [UIImage imageNamed:@"O.png"], nil];
    self.listImageViews = [[NSMutableArray alloc] initWithCapacity:[self.listImageViews count]];

    [self.listImages enumerateObjectsUsingBlock:^(id object, NSUInteger idx, BOOL *stop) {
        // do something with object
        UIImage *image = [self.listImages objectAtIndex:idx];
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.contentMode = UIViewContentModeScaleAspectFit;
        imageView.clipsToBounds = YES;
        [self.view addSubview:imageView];
        imageView.frame = CGRectMake(100*idx, 10*idx, imageView.frame.size.width + 15, imageView.frame.size.height + 15);

        [imageView.layer setBorderColor: [[UIColor blackColor] CGColor]];
        [imageView.layer setBorderWidth: 2.0];
        imageView.contentMode = UIViewContentModeCenter;
        [self.listImageViews addObject:imageView];

    }];

    [super viewDidLoad];
}


- (IBAction)buttonClick:(id)sender {

    NSLog(@"My event is doing!");

    for (UIImageView *item in self.listImageViews) {
        NSLog(@"hi");
        item.backgroundColor = [UIColor redColor];
    }

}

而且 rdelmar 是正确的，您的数组是 UIImage 对象，而不是 NSString 对象。